Endurance was lost in 1915 during the course of the Imperial Trans-Antarctic Expedition led by the renowned explorer, Sir Ernest Shackleton. Over 100 years later, Endurance22 – the research project launched to find the remains of this famous ship – has identified the wreck on the floor of the Weddell Sea.
Shackleton’s expedition
The Imperial Trans-Antarctic Expedition departed from South Georgia in the southern Atlantic Ocean on 5 December 1914, on board Endurance, a three-masted, wooden sailing vessel. The expedition team were hoping to make the first land crossing of Antarctica, from the Weddell Sea via the South Pole to the Ross Sea, but the Antarctic’s harsh conditions soon began to cause difficulties and Endurance never made it to land. On 18 January 1915, the ship became trapped in dense pack ice on the Weddell Sea. The crew attempted to free her but were unsuccessful; by February, temperatures had fallen and the ship was frozen in for the Antarctic winter.
The team remained on board for months, drifting with the sea ice, but eventually the pressure of the ice began to crush the ship. On 27 October, Shackleton and his men were forced to abandon Endurance and set up camp on the ice floes. A few weeks later, on 21 November, they watched from the ice as the ship sank into the ocean, signalling the final death knell for their intended Antarctic land crossing. From this point on, the focus of the expedition became survival. The 28 men spent several months in makeshift camps on the ice, drifting across the Weddell Sea, until early April 1916. At this point, the ice floe on which they had been floating began to break up, forcing them to use the three lifeboats salvaged from Endurance to attempt to reach one of the small islands off the Antarctic Peninsula. Several days later, the party landed on the inhospitable, uninhabited Elephant Island.
The island offered a place to set up a crude shelter, and had seals and penguins that could be hunted for food, but was so remote that there was little chance that anyone would come across the party there. So, on 24 April, Shackleton and five others made a perilous 1,300km journey in a small, open-top, wooden lifeboat, the James Caird, across the wild Southern Ocean, navigated by Endurance’s captain, Frank Worsley, using just a sextant. Upon reaching South Georgia, Shackleton, Worsley, and a third member of the team, Tom Crean, made the 40km trek across the mountainous island to the Stromness whaling station on the north coast. From here, Shackleton arranged for the remaining three men in the James Caird party to be picked up from the other side of the island, and, after several failed attempts, a successful rescue was launched of the men left on Elephant Island as well.
By 30 August 1916, all 28 members of the Imperial Trans-Antarctic Expedition were safe. Although they had not achieved the land crossing that was their original objective, the expedition went down in history as a famous example of bravery, teamwork, and fortitude, through which the team were able to overcome unimaginably difficult conditions with no loss of human life. Now, over a century on, the story of Endurance and her crew has prompted another expedition to this treacherous part of the globe, in search of the lost ship.
Searching for Endurance
The Endurance22 expedition was organised and funded by the Falklands Maritime Heritage Trust, in collaboration with several other organisations, including the Royal Geographical Society (with IBG), History Hit, and Reach the World. The project’s main aim was to locate Endurance on the floor of the Weddell Sea and carry out a non-invasive study of the wreck in order to answer questions about the condition of the ship and gain valuable information that will assist in the protection of the site. Education and engagement were also a key part of the project, with active media teams sharing live updates throughout the trip, keen to engage new – and particularly younger – audiences around the world with the story of Endurance and with the work involved in a polar exploration project. The Endurance22 team also included a number of leading polar scientists, who carried out important studies of the Antarctic environment during the voyage.
The first step in locating Endurance was determining a search area. This was done based on the coordinates recorded by Captain Worsley when the ship sank in 1915. However, he was not able to record the exact position of its sinking as the weather on 21 November was too overcast to use a sextant. Instead, the coordinates represent its assumed location, based on sextant observations taken the next day and Worsley’s estimates of the direction and speed of the ice drift since his last navigational sighting. Nonetheless, these coordinates were the only information the Endurance22 team had to go on, so search efforts were concentrated in a 24km box around this point, in the hopes that Worsley’s estimations were accurate and that the wreck would be found close to this spot.
The Endurance22 expedition set off from Cape Town on 6 February 2022, bound for a 35-day mission in the Weddell Sea. The project was conducted from SA Agulhas II, an icebreaking polar research and resupply ship from South Africa. Throughout the voyage, the team had to contend with the same freezing temperatures, blizzards, storms, and constantly moving sea ice encountered by Shackleton and his men. Although they also found themselves at the mercy of the Antarctic conditions at multiple points throughout the trip, the Endurance22 team were assisted by a wealth of modern technology, including Agulhas II itself, which is able to force passage through up to a metre of solid ice at a speed of 5 knots.
The star of the project, however, was a type of advanced underwater hybrid search vehicle, called a Sabertooth. These vehicles, built by Swedish company SAAB, combine the characteristics of a remotely operated vehicle (ROV), which can be controlled from the surface, and an autonomous underwater vehicle (AUV), which can follow a pre-programmed route independently. These vehicles are able to travel c.160km away from the point where they are launched, and can descend to depths of 3,000m. The vehicles can be fitted with different devices, depending on what kind of search is required, including sonar technology that enables them to survey continuously 1,400m below and on either side of the vehicle, as well as visual technology that can capture 4K resolution footage and transmit live camera feeds to the surface vessel.
The discovery
The Sabertooth underwater vehicles searched the pre-defined search area for several weeks with little success, but eventually, at 4pm GMT on Saturday 5 March, with only five days of the expedition remaining, they came across the wreck of Endurance. The ship is sitting on the seabed, 3,000m deep, just 7.5km south of the coordinates predicted by Worsley. After all the ups and downs of the search, the team experienced a surreal moment of victory as the underwater cameras identified the letters ENDURANCE across the wreck’s stern, with the five-pointed Polaris star (after which the ship was originally named) underneath it. Further examination revealed that the ship was in stunningly good condition – it looked almost exactly as it did on the day that it sank, despite being on the bottom of the ocean for over a century.
The masts have fallen over, but it is believed that this occurred when Endurance was crushed by sea ice and may have acted as a huge parachute as the ship sank, slowing its descent, so that when it hit the seabed 3,000m below, it did not break apart. Except for some damage to the bow where the sinking vessel probably hit the seafloor, the majority of the ship is remarkably intact, sitting upright on the seabed, prow-to-surface. What is more, the timbers are still in fantastic condition as there are no wood-eating microorganisms in this deep, freezing Antarctic water – you can even see the ship’s original paintwork. The Sabertooths’ cameras also identified features including stairways, hatchways, the ship’s anchor and anchor chain, steering wheel, ropes, rigging, and the porthole for Shackleton’s cabin, and even objects left on board when the ship was abandoned, such as boots and crockery, giving the impression that the whole ship has been frozen in time.
The wreck is protected as a Historic Site and Monument under the Antarctic Treaty System, so the expedition team was required to leave it exactly as they found it; they could not touch it, remove any objects, take samples, or interfere with it in any way. Instead, what they took was data. The Sabertooths collected vast quantities of stills and footage to create a detailed picture mosaic of the wreck and its debris field, while also carrying out full photogrammetric coverage of the site as well as a LiDAR (light detection and ranging) survey that will be used to produce millimetre-perfect 3D models of the site. This will enable researchers to study and record the wreck site with the same degree of accuracy as an archaeological survey on land.
As they watched her sink on 21 November 1915, Shackleton and his men must have assumed that their beloved ship would never be seen again. But Endurance’s story did not end on that fateful day: it now has a new chapter. Mensun Bound, the expedition’s Director of Exploration, described the discovery as ‘a milestone in polar history’, and the Endurance22 team have expressed their joy at this once-in-a-lifetime achievement. They hope the project will bring the story of Shackleton and his team to a whole new generation and inspire them to push boundaries and embody the same spirit of exploration.
FURTHER INFORMATION Find out more about the project at https://endurance22.org CWA thanks the Royal Geographical Society (with the Institute of British Geographers) for images and information from their recent exhibition, Shackleton’s legacy and the power of early Antarctic photography.
